The basic input/output system (BIOS) is a very important interface between the computer hardware and operating system (OS). The BIOS is in charge of initially setting and testing during booting the computer hardware to make sure that the hardware can work regularly. If the computer hardware works irregularly, the BIOS will inform the user of the fault. For example, it will show a fault message, e.g. the memory or hard disk malfunctions, on the screen. Further, if the display card isn't set completely, it may use a sound via the speaker to inform the user of the fault. For example, it may use a long or short sound to represent that the memory can be found. In practice, the length of the sound may have different meanings for different companies or different versions.
According to the setup menu of the BIOS, a user can press a key to execute a setting program before the operating system is booted. The user can use the setting program to set date, time, parameters of the hardware (e.g. memory), power saving condition, some setting values of computer peripherals, parameters of the hard disk or passwords.
Moreover, the BIOS also serves as the interface between the computer hardware and operating system. When the operating system needs to use the hardware, it will access the hardware via the BIOS. Since hardware of different companies differ, each company needs its own BIOS to communicate with the operating system.
The BIOS is a program stored inside the read-only memory (ROM). It includes many basic control codes of the computer output interfaces. After the computer is turned on, the BIOS will test the system and read the setting data stored in the complementary metal-oxide semiconductor (CMOS), such as the size of the hard disk, if the optical drive is available, system time, if the shadow random access memory (RAM) is in use, etc.
A mechanism is necessary between components, inside the central processing unit (CPU), or between two units of equipment to coordinate the simultaneous operations of two ends for normal processing of the digital signals. Nonetheless, the time spacing for accessing data is decided by the clock of the system. All digital products have an electronic component, called a “clock generator”. This component will continuously generate voltage pulses with constant time spacing. All of the components inside the product will operate with this clock synchronously. In other words, the digital products need the clock for precise processing of the digital signals, in a manner analogous to the heartbeat of animals. If the clock is unstable, it will cause the transmission error of the digital signals or make the digital equipment malfunction.
Every component on the motherboard has its specific operation frequency and the proportion of the operation frequency of each bus to that of the system is fixed, mostly. In other words, the conventional clock generator usually uses the external frequency of the CPU as a reference frequency and divides the frequency according to the fixed proportion to generate the clocks used for other peripherals.
“Over clock” means making a CPU work with a clock frequency not described in the specification or not supported by the CPU, such as making a Pentium 120 work as a Pentium 133. However, since motherboards now have a new external frequency, a user can change the internal or external frequencies to an abnormal value. This new type of over clock can make the performance of the system much superior to that of past. Even the fastest CPU can perform better this way.
Reference is made to FIG. 1, which is a block diagram of a conventional device capable of detecting a BIOS status for clock setting. It includes a BIOS 10, a clock generating integrated circuit (IC) 12, a CPU 14, a peripheral component interconnect (PCI) port 16, an accelerated graphic port (AGP) 18 and a double data rate (DDR) memory 20.
Its operation method employs the BIOS 10 to send the frequency setting value set by the user to the clock generating IC 12 to make it generate the frequencies necessary for the peripheral components.
Reference is made to FIG. 2, which is a block diagram of a conventional clock generating IC. It includes the BIOS 10, the clock generating IC 12, a logic control circuit 120, a phase-lock-loop (PLL) spread-spectrum unit 122, a crystal oscillator 124, a microprocessor frequency control unit 126, a PCI frequency control unit 128, an AGP frequency control unit 130 and a DDR memory frequency control unit 132.
Its operation method employs the BIOS 10 to send the frequency setting value set by the user to the logic control circuit 120 of the clock generating IC 12. The crystal oscillator 124 of the clock generating IC 12 will generate a clock signal with a constant period and send it to the PLL spread-spectrum unit 122. Subsequently, the PLL spread-spectrum unit 122 will send the clock signal to the logic control circuit 120, microprocessor frequency control unit 126, PCI frequency control unit 128, AGP frequency control unit 130 and DDR memory frequency control unit 132, respectively. Then, the logic control circuit 120 will generate the frequencies necessary for the peripheral components.
At present, users usually raise the operation frequency of the CPU to obtain the best performance. Sometimes, they may raise the frequency of the CPU excessively. This causes a system to be unstable, to crash or to malfunction. In these situations, the watchdog mechanism may also be unable to work. In the worse case, the user needs to delete the data stored by CMOS components. However, this reinitializes the system and causes the user further inconvenient.
Further, after the operating system switches to the sleep mode, the host computer still needs to keep providing some electricity to the clock generator so as to make it able to output the last operation frequency normally when the system is woken up.
If the host computer doesn't keep providing some electricity to the clock generator, the BIOS will reset the operation frequency when the system is woken up. Such a way will require the capacity of the EEPROM used to store the BIOS to be larger. At the same time, it will cause the software engineer more trouble.
Accordingly, as discussed above, the prior art still has some drawbacks that could be improved. The present invention aims to resolve the drawbacks in the prior art.